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maxchess

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Everything posted by maxchess

  1. First, there is no benefit to using EQ mode unless you are intending to image. It takes longer and adds nothing. For imaging however it is vital. Setting your elevation using the dial is not good enough for anything but the shortest focal length. You need to do a proper polar alignment and as the AZGTI has no polar scope I recommend you use SharpCap. Todo that you may need to attach a guide scope/camera combo to your scope. Sounds a pain but process only takes about 10 mins when you have it right. After that the AZGTI works brilliantly
  2. How about M1 Crab Nebula “my way”. It would be interesting to see the many different scope/camera/processing approaches to this small but beautifully textured object. Will the big aperture SCT/newt guys get the best images or can a well processed dithered/drizzled refractor give sharper images? announcing now gives time to plan.
  3. Hi and welcome. if you are at all interested in Astrophotography then it’s all about the mount. Start there and get that right and you will have a firm foundation for future growth. The Heq5 pro as mentioned is well established and will support up to 11kg of telescope. I would start with a basic ED80 type doublet with which you will get some amazing images for a great price. With a shorter focal length you will be able to get 60 sec images unguided on the HEQ5 and then learn about guiding for longer exposures. As suggested above you can then swap scopes and maybe add an 8”SCT like a C8 for visual and with a FR guided imaging. best of luck
  4. If you are thinking of going to La Palma try Casa Rosabel. Dark skies without the hassle and they have decent telescopes. Just take your camera. A little remote but accommodation is excellent. http://casa-rosabel.com/en-gb also in the canaries in general because skies are so dark you can get away with some ground illumination if you go to a shaded area. I took this from a garden in a brightly lit hotel in La Gomera. Just stay away from major towns.
  5. You are probably right, but a Nebula Around Betelgeuse has been reported in the past https://phys.org/news/2011-06-flames-betelgeuse.html
  6. This may be an artifact, but I took this shot of the Orion Constellation from the Canary Islands and it showed a small nebula around Beteleguse. Do you think this is real? The shot was taken with a dual band filter which brings out the Ha. I initially assumed it was a camera artifact, but I took more shots with different camera positions and it was still there. There are some on-line articles about such a nebula. My first reaction was to edit it out, but I think it might be real and only visible because Beteleguse has dimmed by over 50%. What do you think? Max
  7. I am trying to plan out my longer term equipment strategy, rather than go for impulse purchases and would like some advice on dual mounting scopes. At present I have a roll-off shed with steel pier in concrete block. The mount is an HEQ5-Pro, stellar tuned and belt driven which is supposed to have an astrophotography payload of around 11Kg. My main camera is an ASI294MC. Guide camera Lodestar x2. I switch between two scope set ups. (Weight for both includes cameras and filter draw.) • ES102 with 50mm guide scope, FL=714, weight is 7.5 Kg • C8 (not edge) with 6.3 FR and OAG, FL = 1260, Weight is 8kg So clearly I cannot mount both on my HEQ5 Pro. One of the reasons for going with a fixed pier in a shed is that once set up and aligned, I can just push back the roof, align, focus and get imaging in 5 mins. However as targets change I need to swap scopes, rebalance, rewire etc. Not a massive effort but I am wondering if I could dual these scopes and perhaps eventually add something like a WO GT71 FL= 420, weight 2.93 for the wide stuff. So total weight around 19kg. Then maybe in the future go for a Mono camera and filter wheel and even perhaps an C9.25 Edge pushing the weight to around 23kg. To do this I would plan to buy a CEM 60 mount that claims a payload of 27.2 kg, although it is not clear if this is imaging, although I can’t see why anyone would buy one just for visual. I would then just guide with the OAG. So I have two questions: Is this a realistic strategy or would I loose guiding accuracy by loading the mount in this way. Perhaps even compared to keeping the HEQ5-Pro and swapping when necessary. Or maybe just forget the GT71 and C9.25 If I do go down this route, what is the best way of dual or triple mounting? I have read that mounting two dissimilar scopes side by side risks unbalancing the setup, but also that mounting the ES102 on ADM rings risks flexure. Any other advice or observations most welcome. Thanks Max
  8. I am not going to stick my neck out and give you a recommendation but I will give you my experience. I have been imaging for only about 2 years (a surprising small number of clear nights!) and started with a cheap 90mm scope on a standard HEQ5 using a DSLR and got some OK images. I then bought a second hand C8 and used a focal reducer so I was imaging with a FL of about 1250 (6.3 x 2000) , again a few OK images but the angular view was so tight I needed to guide, which itself is a challenge with a C8 unless you use an OAG. I belt modigied the HEQ5 which was better. I decided to drop the focal length and got a ES102 F7 triplet which has a FL=714. I found this was much more suited to the mount and I could guide easily with a 50mm guide scope and a cheap camera. I also found that there are an abundant number of targets suited to the FOV of this scope. I can get good results with exposures of 60 - 120 secs. I can also add a Focal Reducer to widen the FOV if necessary. All in all this combination was much more forgiving and within the tolerance of the mount. My next revelation was buying an ZWO ASI294MC-Pro, not cheap, but compared to a DSLR so much more sensitive and with much lower noise and of course it doesn't need to be astro modified. Even at Unity gain of 120, stars were blowing out if I went much more than 60 secs, so that made imaging much easier by doing lots of 60 sec subs, plus calibration frames. My skies are Bortle 5, so my next buy was the Optolong L-eNhance dual-bandpass narrowband filter. For targets with strong nebulosity like the Veil Nebula this produces great results. I toyed with the idea of going for a mono camera and filter wheel, but I am not ready for the jump, maybe next year. My conclusion out of all this is go for a balanced set up and keep the focal length as short as you can for the targets you want. In parallel I found I needed to work on my processing. Once stacked in DSS, I use Startools, which is workflow oriented and allows you to get good results with a simple "automatic" approach and then to build on this by exploring and improving each stage. I have now resolved to improve my imaging and processing with what I have, using Astrobin for inspiration and motivation, before I think I need more stuff. To paraphrase CSNY: If you can't get the kit you love, love the kit you have. All the best Max
  9. NGC6960 Witches Broom, taken with my shiny new ASI294MC with Optolong L-eNhance Dual-Bandpass Narrowband Filter on an ES102 scope on HEQ5_Pro: 60 x 60 secs + 20 Darks, 20 Flats, processed in Startools. Shot in a fortuitous gap in the clouds.
  10. This portrait of M27 the Dumbbell Nebula really stunned me when it first emerged from DSS, it only needed a light touch in Startools. Taken with an ASI174MC uncooled on a ES102 triplet, under Bortle 5 Skies: 80 x 60 secs + 20 Darks + 20 Flats. A real gem of the night sky. Hope you like it. Max
  11. I have decided to buy an OSC CCD and have narrowed it down to a choice between AS129MC Pro and the ASI183MC pro. I would welcome some advice and comments on my reasoning. First, I know there is a good argument for going mono, but that’s for the future. I want to take it one step at a time. I am just about getting my head round guiding. My kit is a HEQ5-Pro Rowan Belt modified with mainly Explore Scientific ED APO 102mm f/7 focal length 712mm permanently mounted on a pier.. I also have a Celestron C8 but that’s for later. Until now I have been imaging with a Canon450D moded and a Canon 2000D. I have an ASI178MC (not cooled) that I bought to experiment with last year. I also have travel gear consisting of an AZ Gti WiFi on which I sit my DSLR with a Cannon 300mm lens, which is great for big targets like M31, Rosette Nebula etc After extensive reading on Forums etc I am leaning towards the ASI294MC-Pro. (but tomorrow I might change my mind) My reasoning is that the ASI1294 has a larger sensor size, 14 bit ADC vs 12 on the183; and larger pixels, and a greater full well capacity. So this means that the FOV will be only just a bit tighter than the my DLSR so with my ES102 I can still get good images of larger targets like M42 especially if I add an FR. Without the FR I can get smaller targets. I should also be able to use it with my Canon 300mm lens when traveling. It should also work well with my C8 when I start using that. I have also read that the larger pixels at 4.63um are more forgiving than the ASI183 that has 2.4um pixels especially when focussing. The ASI294 also has a much greater full well capacity, in theory providing greater dynamic range and less chance of blowing out stars. But I have a nagging doubt, because the ASI183MC pro although it has a smaller sensor size, is still quite decent and the tiny pixels mean that it has a resolution of 20mp compared with the 11mp of the ASI1294. So am I turning my back on greater resolution for my shorter focal length scopes? In the world of DLSR 20mp beats 11mp any day. Plus the ASI183 has an 84% QE! What brought it home was a test exposure I did with the old ASI178MC that also has 2.4um pixels, but a much smaller sensor. Using the ES102 I took 50 x 30 sec exposures of M27 (dumbbell) and compared them with results from the 450D on the C8. The FOV is the same, but the 178MC results were so much better. Any views most welcome.
  12. I have the AZGTI mount which I use in EQ mode. On it I have a 300mm canon lens with either a DSLR or an ZWO camera. The most balanced way is to use a Tripod Collar, round the lens £11 on Amazon and attach that to a short Vixen type dovetail bar around £20 , although you can pay up to £100. Make sure you get one with a captive screw designed for mounting camera, like this one:. This arrangement allows you to balance the camera in the Vixen mount by sliding the bar. The ZWO adapter you quote should work too.
  13. Martin, Can you descibe how you fitted your garage door opener? I am planning to upgrade my obs rails to female vee section steel wheels running on male vee section steel rails and then to add a garage door opener. The Easygate system you linked to looks good value for money.
  14. Do you already own an DSLR? If so have you used it with the Nextstar? If not I suggest you look for a used Canon 450D, ideally astro modified.
  15. My Christmas present was a Canon 300mm f4 lens to use as my travel scope instead of a bulky refractor, but to go with DLSR and AZ/GTI portable mount. So I took it to La Palma to get some winter sun and dark skies. Playing with Stellarium told me that with a 78degree tilt I should be able to get both M42 and the HH Neb in one frame, no mosaic. It's true you can! So despite losing half my subs to a faulty cable I got 60 x 30 sec exposures, which at f4 in really dark skies got me a reasonabe result. Taken on March 12th in sunny la palma : Canon 2000d unmodified, 300mm f4 lens, on AZ-gti mount. Controlled by ATP software (great canon autofocus control, wifi connect to mount, plate solving for positioning) processed with DSS, Startools and Lightroom. 60 x 30 sec subs +20 each of darks, lights, bias
  16. Thanks all, for some really helpful advice. I have only been imaging a year and just started exploring guiding. Before that I was doing up to 120 secs unguided and getting (for me) decent results. My best image was https://astrob.in/373575/0/ 160 x 60" unguided and I am interested in your comments on what is achievable with my HEQ5 Pro if I guide it. At present I am trying just to get sub 2 arcsec guiding but seem to be getting bad backlash related errors errors. Once achieved it sounds like I need to stick to my DLSR through the ES102.
  17. I am experimenting with guiding, and want to understand what I need to guide my ES102 with a ASI 1784 on an HEQ5-Pro. I have an Orion SSAG mono guide camera and its 50mm guide scope, fl= 162mm. I also have an ST80 fl=400mm. I am having a bit of trouble guiding with the ST80 using PHD2. I get large guiding errors. I am considering going back to the Orion 50mm. However when I calculate the FOV for the ES102 + ASi1784MC I see it is 0.6° x 0.4°, which is equivalent to DLSR on a 2100mm focal length scope! Therefore I wonder if the 50mm/162mm FL will cope. In the discussions on Focal Length for guiding I only find references to matching the FL of the main and guide scope, not the FOV, but surely its the FOV that affects the apparent angular motion and therefore the required guiding accuracy? Or have I missed something.?
  18. OK, sounds good. Moon washed out last nights images so waiting for Moon to disappear before experimenting further.
  19. This is the article that gives the example settings for long exposures. It is a different sensor, but the principal seems to be that for Highest Dynamic Range on long exposures you set gain to 0, offset 10. In the example they have unitary gain as (G: 139 O: 21). So I assume that G=0 maximizes well depth and offset 10 lifts the lower values. In my simplistic way of thinking I assume that with G=0, O=10 I can usefully increase exposures until the highlights reach saturation, at which point I am getting the best dynamic range, ie making optimum use of the ADC to record the widest range of values in the most detail. I notice from Astrobin that many ZWO camera users use large numbers of relatively short exposures 60-120 secs , rather than DLSR users who go for fewer much longer exposures. Still struggling with this camera, will process last nights Moon affected images later.
  20. To be safe I am trying some captures at Gain=10 , Offset=10 on M81, (20 x 120 secs) but with a full moon they are likely to be poor. M81 is about as far away as I can get from the Moon. However lights so far are showing minimal Amp Glow. Hopefully with Darks, Lights & Bias I can eliminate it.
  21. I have the uncooled version of this camera and the same problem. I tried Gain=200 and got what looked like a star shaped light leak in one corner just like yours. I also took flats & Bias frames, but they did not help much. I assumed it was a problem with my scope, but found its was AMPGLOW, see this ZWO article. I tried taking 90 second Darks at various levels of Gain and found it diminished until it was virtually invisible at Gain=10 . To see the effect take a Dark into your processing program and stretch it. ZWOs solution is to control via Darks and disable any dark optimization feature of your calibration program eg DSS. They say that this effect only occurs in "specialist" sensors and not in those used for DLSRs. I was staggered, sounds like a design fault to me. These guidelines appeared in another ZWO post: Unity Gain ==> Gain: 180 Offset: 25 Highest Dynamic Range ==> Gain: 0 Offset: 25 Lowest Read Noise ==> Gain: 270 Offset: 340 So my interpretation is to go for Gain: 0 Offset: 25 for DSOs on long exposure and disable dark optimization. Waiting for moonless/cloudless night to try this out. Any other experiences most welcome. Never had this problem with my trusty 450D.
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